1. Field of the Invention
The present invention is related to a series of polyesters based upon the reaction of dimer acid, dimer alcohol and Guerbet alcohol. The resulting polyester is a high molecular weight product that is well tolerated by the skin and has outstanding emolliency. The Guerbet alcohol, being mono hydroxyl is a capper portion of the polymer, the dimer alcohol is a chain extender having two hydroxyl groups and the dimer acid is a diacid that reacts with the hydroxyl groups on the Guerbet and dimer alcohol to make the polyester.
2. Description of the Art Practices
There is a long felt desire to develop an ester that gives gloss to the skin when applied from oils or applied from emulsions. An added aspect of the present invention is the fact that the compounds are polymeric. This has two very important implications on the use of the materials of the present invention. The polymeric nature means the compounds do not penetrate the skin. The fact that these molecules remain on the skin, increases gloss and provides a less irritation to the skin. They also provide a gloss that is more long lasting.
U.S. Pat. No. 5,786,389 issued July 1998 to O'Lenick, incorporated herein by reference, describes the use of a Guerbet ester of castor for gloss. The compounds are a simple ester made by the reaction of castor and a specific mono functional alcohol to produce an ester. The products of this patent are neither polymeric, nor do they involve reaction of the hydroxyl group in the castor molecule. We have discovered that higher gloss, lower irritation and better durability of gloss results when one makes the polymers of the present invention.
U.S. Pat. No. 6,342,527 to O'Lenick, Jr., et al. issued Jan. 29, 2002 entitled Polymeric castor polyesters relates to a series of polyester compounds derived from castor oil. Castor oil, a hydroxy containing oil, can be esterified with a fatty acid to produce an intermediate having both an ester and triglyceride functionality. By selecting the ratios of reactants, the castor can be a partially substituted with fatty acid leaving some unreacted hydroxyl groups. The number of remaining hydroxyl groups, and the type and concentration of diacid used to react with the unreacted hydroxyl groups, results in a controllable polyester. The control of molecular weight and degree of polymerization is critical to functionality of the product.
U.S. Pat. No. 6,706,259 issued Mar. 16, 2004 to Gardner, et al., incorporated herein by reference, discloses hydrolytically stable esters. These esters are simple esters of the dimer alcohol and a mono fatty acid. The compounds are not polyester, since no crosslinking ester is included in the molecule and no capper is used.
U.S. Pat. No. 6,537,531 issued Mar. 25, 2003 to Gardner, et al., incorporated herein by reference, discloses hydrolytically stable esters based upon Guerbet acids. Again like the '259 reference above, these esters are simple esters of the dimer alcohol and a mono Guerbet branched fatty acid. The compounds are not polyester, since no crosslinking ester is included in the molecule and no capper is used.
The Gardner references show long felt need for products that do not penetrate the skin, provides gloss and does not effect trans epidermal water loss.